- Avengers - Joss Whedon is 2nd to none at action and he is just slightly younger than me so I suspect we had the same reading material as tweens -- Marvel Comics. With The Avengers he was in the element of his life.
- Iron Man 3 - Sir Ben Kingsley for the win: "Well I panicked, but then I handled it." Perfect blend of comedy and action.
- Thor: Dark World - arguably should be second place with a better finish than IM3, but lacks to top quality whimsy of IM3 at it's best.
- Dark Knight/Dark Knight Rises - the best non-Marvel properties. Striking for the unfashionable political themes that the action allows you to ignore if you want.
- The Matrix - a landmark that kicked off the action film pinnacle.
- Spiderman - a revelation at the time about how astonishingly good superhero movies could be and a bellwether for Marvel properties to come.
- Cap: Winter Soldier/Iron Man 1/Spiderman 2 - this is where things get murky and I lose interest in ratings...
Honestly, I have to admit this list is probably biased to my personal experience. I have written previously about how the tone and tenor of Marvel Comics from roughly the 70's-ish has come to dominate the blockbuster movie milieu. Beyond that, actually: the whole era of hyper-ironic, self-referential, magic realism that forms a huge part of our pop culture can, I think, be traced to 13-year-olds like me following Spiderman and The Avengers every month. In that sense this list may have been self-fulfilling. Is Marvel-ism ascendent because it is superior or is it just the cultural and economic influence of people like me forcing our opinions on the rest of you? If it's the later, then all I can say is you're lucky we're in charge otherwise The Expendables would be sincere and serious. For a more critical and less Marvel-oriented view of action movies you can watch this video.
Various aspects of culture peak at different times, either because of fashion or technology or just happenstance. For example, today there is fine music being produced as always, but no musical genre is at it's peak right now as say, rock was in the late '60s or the times of the Great American Songbook in the 30s and 40s. I don't believe any form of writing is at it's peak right now, although good writing is happening in so many different forms and being delivered in so many different ways that it's hard to tell. TV peaked just recently -- remember the days when Sopranos and Deadwood and The Wire were running simultaneously? TV is still good, but not what it was. I'm ranting about action movies because they are the aspect of our culture that is at its peak right now. Movies, in general, are not. They are, in fact, mostly awful, but action films are peaking. Even what we would consider an average action film today -- Edge of Tomorrow, for an example -- would have been a revelation 15 or 20 years ago. They may not be great and eternal works of art, but action films are what we do best at the moment. It's probably worth paying attention.